Such an air-conditioning system is described, e.g., in the book Bosch, Kraftfahrtechnisches Taschenbuch (“Automotive Handbook”), 23rd Edition, Vieweg, 1999, ISBN 3-528-03876-4, pages 778 and 779. Accordingly, it is provided in such air-conditioning systems to use automatic controls having a program selection for automatically setting a desired interior temperature, air quantity and air distribution. These variables are said to be always tied to one another and not freely modifiable. A provided electronic control-unit is said to measure both all important influencing and interfering variables as well as the temperature selected by the occupants and to form from this continuously a temperature setpoint value. The temperature setpoint is said to be compared to the actual temperature and the ascertained difference is said to generate reference variables for controlling the heating, cooling and air quantity. Another function is said to activate the clack valve control system for the air distribution—as a function of the program set by occupants. It is said to be possible to influence all control loops by manual input. The temperature setpoint ascertained by the control system is said to be achieved by water or air control. It is said to be possible to bring the air quantity to the setpoint value by setting various blower steps or in a stepless manner. Generally, this is said to be a control system without actual value processing. At high speeds, this device is said to be insufficient because the ram pressure occurring in that case is said to increase the output volume. With increasing driving speed, a special control system is said to be able first to reduce the blower speed until it comes to a standstill and, if the ram pressure continues to rise, to limit the entering air flow via a throttle valve.